本文给出了拓展基尼系数的一个等价定义,给出拓展基尼系数组群、要素分解的统一形式。对2009年我国城乡居民食品消费数据进行结构性分析,结果表明:1拓展基尼系数是不平等厌恶参数的增函数,最小值为0、最大值为1-S1/P1;2随着不平等厌恶参数的增大,各个组群或要素对不平等边际效应的方向保持相对稳定;3城镇居民在外餐饮、肉禽及制品、水产品类支出份额的增加,对食品消费不平等产生消极的边际影响。This paper promotes an equivalent definition of the extended Gini coefficient,and proposes an unite decomposition formula of the extended Gini coefficient by subgroups and factors.Applying the formula to 2009 China's food consumption data yields several interesting results as follows: ①the extended Gini coefficient is an increasing function of aversion inequality parameter,with the minimum 0 and the maximum 1-S1/p1;②with the parameter increasing,the relative marginal effects of subgroups or factors on the extended Gini coefficient have rather stable action direction;③it will has a negative effect on food expenditure inequality to increase dining out,meat,poultry and processed products,aquatic products expenditure ratio.国家社会科学基金“教育公平与效率统计测度及其关系的实证研究”(BFA090018)资助;福建省统计学重点实验室(厦门大学)的资
